A wire grid polarizer (WGP) can primarily transmit one polarization (e.g. p-polarization) and primarily reflect or absorb an opposite polarization (e.g. s-polarization). High reflectivity of the opposite polarization (e.g. high Rs) can be important in some applications if both polarized light beams are used (e.g. s & p). High absorption/low reflectivity of the opposite polarization (e.g. low Rs) can be important in other applications if reflection of this polarization (Rs) will interfere with the optical system. For example, the reflected s-polarization can cause ghosting in an image projector. Some WGPs are designed for high reflection and others for high absorption of the s-polarization.
High transmission of one polarization (e.g. high Tp) can be an important feature of WGPs in order to minimize light-source power requirements. Low transmission of the opposite polarization (e.g. Ts) can be important for improved light image resolution. Some applications, including some image projection systems, require very low Ts, because any Ts above a negligible amount will distort the projected image.